The invention relates to a lead-through device for a wall, having a first and a second pipe fitting element, which can be connected to one another through a through-passage in the wall, wherein the first pipe fitting element has a flange, which bears a sealing element which, in the connected state of the two pipe fitting elements, abuts with fluid-sealing action against a wall portion adjacent to the through-passage in the wall, and wherein the second pipe fitting element has arranged on it a supporting element which, in the connected state of the two pipe fitting elements, is supported on the other side of the wall, as seen with respect to the sealing element of the first pipe fitting element.
In a tank or container having a wall, access is frequently required to the interior of the tank or container in order for example for a fluid, which may be liquid or gaseous, to be channeled into or out of the same. For this purpose, lead-through devices of the type mentioned above are known. It is regularly necessary for the lead-through device to provide for a connection between the one side and the other side of the wall which is fluid-tight toward the outside. This is important, in particular, for fuel tanks, in particular plastic fuel tanks, in which, for example during refueling, liquid fuel is introduced and from which, for example for venting purposes, gaseous fuel vapors are routed out. While it is therefore the case that, on the one hand, liquid fuel should be introduced into the tank and, on the other hand, gaseous fuel should be routed out from the tank, strict emission standards stipulate that there should be no fuel vapors, or even liquid fuel, escaping. While this can be realized in a comparatively straightforward manner for the tank wall by way of a construction with a plurality of layers, and use being made of a layer which is impermeable to fuels, openings in the tank wall for lead-throughs are always critical.
A lead-through device of the type mentioned above is known from WO 2006/032672 A1. The supporting element there is designed in the form of a further flange which, like the flange on the first pipe fitting element, is connected rigidly to a tube body of the pipe fitting element. In the screwed-together state of the two pipe fitting elements, the two flanges abut against the wall, in surface contact therewith, wherein a respective sealing ring in a groove provided in the flanges is intended to provide for sealing. This does not take into account the fact that, over time, the wall undergoes expansion and shrinkage, and therefore permanent sealing of the screw connection, once established, is not ensured.
Based on this it is the object of the present invention to provide a lead-through device for a wall of the type mentioned above which straightforwardly ensures reliable and permanent sealing toward the outside.
The combination of features in patent claim 1 is proposed to achieve this object. Advantageous embodiments and developments of the invention result from the dependent claims.